Most specifically of all, he has pointed out that within the reality of Doctor Who itself, there are no references to the numbers people use to refer to individual incarnations of the Doctor—whether that’s formally referring to him as the Tenth Doctor or giving him the informal nickname of Five or Seven. There may be some happy coincidences—such as the number 11 on the Doctor’s hotel room in “The God Complex,” but no numerical names.

There are also references to the amount of regenerations the Doctor is allowed, there have been several visual lists of the different incarnations, but as far as everyone who meets and deals with the Doctor is concerned, there is only the Doctor, even when there are two of them together at the same time.

So, when fans argue over whether to renumber the Doctors in the wake of the appearances of John Hurt’s War Doctor between those of Paul McGann and Christopher Eccleston, he has one clear message:

“You are all wrong! He has never called himself the anything-th Doctor in the show.”

He explains: “If the Doctor was a real person and walked in here, and you said, ‘Which incarnation are you?’ he’d have to think, just as you’d have to think about how many houses you’ve lived in. He never thinks of himself as a numbered Doctor. The Twelfth Doctor means the twelfth actor to have played the lead in Doctor Who. That’s all it means. There is no such character as the Twelfth Doctor and never has been.”

Which does at least suggest that, for the purposes of discussing the history of the show, Peter Capaldi is the Twelfth Doctor. Just don’t say it to his character’s face.

Steven continued: “It’s a long time into the show before any such nonsense ever comes up. It’s purely us lot, us fans, wittering on about calling him the Third or the Fourth Doctor – which is actually quite an unpleasant thing to do. It doesn’t feel right at all when you type that. I had to do that for the [50th] special. It was the Tenth Doctor, the Eleventh Doctor, and it felt like a betrayal, in a way. But what else could you do?

“Out of curiosity I looked at what they did in “The Five Doctors.”* They didn’t number them at all. Do you know what they called them? The Hartnell Doctor, the Pertwee Doctor…”

But that also seems wrong, somehow, given that the Whoniverse does not, as far as we know, contain anyone directly related to the Doctor who has the surname Pertwee, or Hartnell, or even Capaldi.